Water contaminant measurement system and methods for measuring concentration levels of contaminants in water

Abstract

A contaminant measurement system is provided. The system is operable to detect and measure a concentration level of a preselected contaminant, e.g., lead, in water disposed within a chamber of the system. The system includes a detection agent that is operable to interact with the preselected contaminant in the water. The detection agent can be a plurality of polymeric beads or a membrane, for example. The system has a sensing circuit that includes a pair of electrodes spaced from one another and both at least partially disposed in the water. A controller is communicatively coupled with the sensing circuit and is configured to receive one or more electric signals from the sensing circuit. The controller determines a parameter indicative of the concentration level of the preselected contaminant based on the one or more electrical signals. The controller then determines and outputs the concentration level of the preselected contaminant.

What is claimed is: 
     
       1. A contaminant measurement system for measuring a concentration level of a preselected contaminant in a volume of water, the contaminant measurement system comprising:
 a housing defining a chamber configured for receipt of the volume of water; 
 a detection agent disposed in a basket in the volume of water in the chamber; 
 a sensing circuit having a first electrode and a second electrode both disposed in the basket at least partially in the volume of water in the chamber, the first electrode spaced at a distance from the second electrode; and 
 a controller in electrical communication with the sensing circuit, the controller configured to: 
 receive one or more electric signals from the sensing circuit, the one or more signals being captured as the detection agent selectively interacts with the preselected contaminant in the volume of water for a first time period; 
 determine a parameter value indicative of the concentration level of the preselected contaminant in the volume of water based at least in part on the one or more electric signals; 
 determine the concentration level of the preselected contaminant in the volume of water in the chamber based at least in part on the parameter value, and wherein in determining the concentration level of the preselected contaminant, the controller is further configured to: 
 calculate a parameter difference value for the determined parameter value, wherein the parameter difference value for the determined parameter value is descriptive of a base reference parameter value subtracted from the determined parameter value; and 
 correlate the calculated parameter difference value for the determined parameter value to the concentration level of the preselected contaminant in the volume of water in the chamber utilizing a trend line determined during a calibration specific to the contaminant measurement system; and 
 output the concentration level of the preselected contaminant in the volume of water in the chamber. 
 
     
     
       2. The contaminant measurement system of  claim 1 , wherein the detection agent is a plurality of beads, wherein the plurality of beads is a plurality of sodium hydroxide treated polyacrylonitrile homopolymer beads. 
     
     
       3. The contaminant measurement system of  claim 2 , wherein the preselected contaminant is lead. 
     
     
       4. The contaminant measurement system of  claim 1 , further comprising: a display device communicatively coupled with the controller, and wherein the concentration level is output by the controller to the display device so that the determined concentration level is presented to a user. 
     
     
       5. The contaminant measurement system of  claim 1 , wherein the first electrode is formed of a first electrically conducting material and the second electrode is formed of a second electrically conducting material dissimilar to the first electrically conducting material. 
     
     
       6. The contaminant measurement system of  claim 5 , wherein the first electrically conducting material of the first electrode is copper and the second electrically conducting material of the second electrode is graphite. 
     
     
       7. The contaminant measurement system of  claim 1 , wherein the housing has an inlet port defining an inlet of the chamber and an outlet port defining an outlet of the chamber, and wherein the contaminant measurement system further comprises:
 an inlet supply conduit providing fluid communication between a water source and the inlet of the chamber; 
 an inlet valve positioned along the inlet supply conduit and operable to selectively allow the volume of water to flow into the chamber; and 
 an outlet supply conduit in fluid communication with the outlet of the chamber, the outlet supply conduit operable to allow the volume of water to drain from the chamber. 
 
     
     
       8. The contaminant measurement system of  claim 1 , wherein the parameter value is indicative of at least one of a voltage between the first electrode and the second electrode, an electrolytic current flowing between the first electrode and the second electrode, a conductivity of the volume of the water within the chamber, and a resistivity of the volume of water within the chamber. 
     
     
       9. The contaminant measurement system of  claim 1 , wherein in performing the calibration, the controller is configured to:
 ascertain the base reference parameter value indicative of the concentration level of the preselected contaminant in a volume of water having a first known concentration level of the preselected contaminant; 
 ascertain a plurality of reference parameter values each indicative of the concentration level of the preselected contaminant in respective reference volumes of water each having a known concentration level of the preselected contaminant; 
 calculate a parameter difference value for the ascertained base reference parameter value and each of the plurality of ascertained reference parameter values, wherein the parameter difference value for each of the plurality of ascertained reference parameter values is descriptive of the ascertained base reference parameter value subtracted from a given one of the ascertained reference parameter values, and wherein the parameter difference value for the base reference parameter value is zero; and 
 determine the trend line specifying the parameter difference value versus the concentration level based at least in part on the calculated parameter difference values. 
 
     
     
       10. The contaminant measurement system of  claim 9 , wherein the determined parameter value used to determine the concentration level of the preselected contaminant in the volume of water within the chamber is based on one or more final signals of the one or more signals received at an end time of the first time period. 
     
     
       11. The contaminant measurement system of  claim 10 , wherein the end time of the first time period is determined based on the determined parameter value reaching a steady state. 
     
     
       12. The contaminant measurement system of  claim 1 , wherein the controller is further configured to:
 store a plurality of data points representative of the determined parameter values over the first time period; 
 generate a parameter trend line based at least in part on the stored plurality of data points; and 
 predict the parameter value based at least in part on the parameter trend line. 
 
     
     
       13. The contaminant measurement system of  claim 12 , wherein the parameter value used to determine the concentration level of the preselected contaminant in the volume of water within the chamber is based on the predicted parameter value. 
     
     
       14. The contaminant measurement system of  claim 12 , wherein the parameter value is indicative of at least one of a voltage between the first electrode and the second electrode, an electrolytic current flowing between the first electrode and the second electrode, a conductivity of the volume of the water within the chamber, and a resistivity of the volume of water within the chamber. 
     
     
       15. The contaminant measurement system of  claim 12 , wherein the parameter trend line is a decaying exponential function. 
     
     
       16. The contaminant measurement system of  claim 1 , wherein the controller is further configured to:
 cause a voltage to be applied across the first electrode and the second electrode both at least partially disposed in the volume of water within the chamber. 
 
     
     
       17. The contaminant measurement system of  claim 1 , wherein the first electrode and the second electrode are connected to a top cap that is removably seated on the housing. 
     
     
       18. The contaminant measurement system of  claim 17 , wherein the basket is connected to the top cap, the basket defining a basket chamber in which the detection agent is disposed, the basket chamber being in flow communication with the chamber of the housing.